Networks-on-Chips (NoCs) are an emerging communication topology paradigm in single chip VLSI design, enhancing parallelism and system scalability. Processing units (PUs) connect to the communication topology via routers, which are responsible for runtime establishment and management of inter-PU communication channels. Router design directly affects overall system performance and exploited parallelism. In this paper, we present a highly parametric NoC architecture, MACS, providing increased system speed, designer flexibility, and scalability as compared to previous methods. In addition, MACS enhances inter-PU communication using a circuit-switching technique with dedicated, high frequency communication channels. Compared to previous work, MACS offers a 5x increase in operating frequency and a 2x reduction in area overhead.